Taxonomy term

january 2018

Once considered detrimental to ecosystems and nuisances where, for example, dams flooded farmland, beavers have been rhetorically touted in recent years as a potential boon for wetland health and water conservation. Anecdotal accounts and qualitative findings have suggested beavers improve water quality and availability in drought-stressed ecosystems, but just how much influence they have was not known. In new research, scientists have examined two creeks in Nevada to directly measure how effective beaver dams are at slowing water flows and storing water through the dry summer months.

Amid the well-publicized discussions over healthcare, tax reform, the federal budget and disaster aid in summer and fall 2017, a quieter conversation over mining legislation reform was also going on in Congress. Democrats and Republicans in both chambers introduced legislation concerning abandoned mine lands (AML) in the current congres­sional session, and while no new bills have been passed, discussions continue on the contentious subject.

Blowing dust is one of Arizona’s deadliest weather-related hazards. Between 1955 and 2011, brownout conditions created by dust storms caused more than 1,500 motor vehicle accidents across the state, resulting in 157 fatalities and more than 1,300 injuries, according to a 2016 NOAA Technical Memorandum.

Fifty years ago this month, on Jan. 25, 1968, a massive bonfire built of red fir bark atop Glacier Point in Yosemite National Park was burned down to embers and, promptly at 9 p.m., and for the last time, pushed over the cliff edge to create a flaming cascade for the viewing enjoyment of tourists gathered below. The spectacle, called “firefall,” had been a beloved Yosemite tradition for nearly a century.

Coal burning produces an array of chemicals and particulates that, when released into the atmosphere, contribute to pollution, poor air quality and threats to public health. Measurements of particulate air pollution typically focus on particles called PM2.5, which have diameters of 2.5 micrometers or less. This group includes nano-sized particles, although these bits of minerals, dust and organics often go undetected because of their tiny size. In a new study, researchers sampling a coal ash spill have unearthed a type of nanoparticle not previously known to be produced by burning coal. While the particles might be useful in detecting pollution problems, they may also have consequences for human and environmental health.

Large Middle Eastern rivers like the Nile, Tigris, Euphrates and Tiber were critical for the development of early urban societies in Egypt, Mesopotamia and Ancient Rome. And researchers have long thought that the rise, and eventual decline, of cities in the ancient Indus Civilization, which spread across about 1 million square kilometers of what’s now northwestern India and Pakistan from roughly 4,600 to 3,900 years ago, also depended on major rivers, namely those emerging from the Himalayas. But a new study looking at river sediments from the time of the civilization and earlier suggests that wasn’t the case for every ancient Indus city; some may have benefited from being farther away from large rivers and their periodic floods.

Paleontologists have long hypothesized that a land bridge between present-day Siberia and Alaska served as a gateway for fauna to migrate between Asia and North America during the Cretaceous, but they have unearthed little evidence that directly supports this idea. Now, researchers have found an Asian dinosaur track assemblage in North America, a discovery that backs the longstanding hypothesis.

Not many people are able to combine their work and hobbies the way Craig Clements, a meteorologist at San Jose State University in California, has. “I was always interested in mountain weather,” he says. “I got into meteorology through my interest in mountaineering and climbing.”

Tsunamis are one of the most destructive natural hazards on Earth, sometimes even upstaging the major earthquakes that send the waves surging across entire ocean basins. Knowing when, where and how severely tsunamis have struck coastlines in the past is valuable for countries trying to prepare for the impacts of future tsunamis. But distinguishing tsunami deposits in geologic paleorecords from deposits left by more common storm waves is notoriously difficult. Researchers recently highlighted this challenge by taking a hard look at tsunami- and storm-wave records around the Mediterranean Sea over the last 4,500 years. The findings may serve as a cautionary tale for scientists interpreting tsunami records elsewhere in the world.